Portable power source



FIG. 1 is a perspective view of the portable power source;

FIG. 2 is a side view of the portable power source;

FIG. 3 is a front view of the portable power source;

FIG. 4 is a back view of the portable power source;

FIG. 5 is a top view of the portable power source; and,

FIG. 6 is a front view of the portable power source shown in an open condition. 

The ornamental design for a portable power source, as shown and described. 